Multitudes of patents exist for automatic swimming pool cleaners and components of such cleaners. U.S. Pat. Nos. 4,642,833 to Stoltz, et al. and 4,742,593 to Kallenbach, for example, illustrate and describe various pool cleaners and valves useful in their operation. U.S. Pat. No. 5,014,382 to Kallenbach discloses other such pool cleaners, while U.S. Pat. No. 5,315,728 to Atkins illustrates certain components of automatic pool cleaners. U.S. Pat. Nos. 5,317,777 to Stoltz and 5,450,645 to Atkins describe yet other exemplary pool cleaners and components.
U.S. Pat. No. 4,835,809 to Roumagnac details, in some embodiments, an automatic swimming pool cleaner designed to be connected to the "water recycle" or "return" mouth of a swimming pool. This cleaner, generically categorized as a "pressure-side" cleaner, receives pressurized water entering the pool through the return mouth. The pressurized water in turn enters the cleaner, passes through an injection orifice, and is exhausted through a tube or pipe to propel the cleaner about surfaces of a pool. The flow of pressurized water within the cleaner additionally lowers the pressure therein, aspirating debris-laden water into an orifice denoted the "aspiration mouth." From the aspiration mouth the debris-laden water passes through a filter inside the cleaner (thus removing debris from the water), thereafter joining the pressurized water being exhausted through the tube or pipe.
U.S. Pat. No. 5,546,982 to Clark, et al. discloses improved versions of cleaners of the Roumagnac patent. An automatic pool cleaner described in the Clark, et al. patent includes a series of curved wipers protruding from its bottom. The wipers spiral inward toward a central inlet (or "aspiration mouth" in the nomenclature of the Roumagnac patent), causing debris-laden water to flow in the form of a vortex about the inlet when the cleaner operates. As with other existing automatic swimming pool cleaners, those illustrated in the Clark, et al. patent remove the debris from the flowing water mechanically.
None of these automatic pool cleaners thus operates to sanitize or otherwise treat pool water chemically. Instead, pool water is traditionally treated chemically through placing chlorine-containing tablets in the pump assembly of the pool, for example, and by pouring algicide or other liquids (or granulated solids) directly into the pool volume. Positioning chlorine tablets in a pump assembly can be both time consuming and tedious, however, often prompting consumers to forego the process entirely and simply drop the tablets in the skimmer baskets of their pools. Alternatively, commercial versions of purification vessels such as those described in U.S. Pat. No. 5,660,802 to Archer, et al. may be plumbed externally of the pools, often adjacent swimming pool pumps. While these latter vessels are useful in sanitizing pool water, none contemplates automatically treating water both chemically and mechanically within the pool itself.